Abrasive belt cutter bar grinding machines



4 Sheets-Sheet l /N VE N 7' 0/? CHAR-LE5 H, BAN/(6 Mm w n MN m Jw ,0, NW mu -o w N 4r a -------%|-|L F Dec. 27, 1955 c. A. BANKS ABRASIVE BELT CUTTER BAR GRINDING MACHINES Filed May 14, 1953 Dec. 27, 1955 c. A. BANKS ABRASIVE BELT CUTTER BAR GRINDING MACHINES Filed May 14, 1953 4 Sheets-Sheet 2 INVEN TOR. CHARLES H. BAN/f6" 27, 1955 c. A. BANKS ABRASIVE BELT CUTTER BAR GRINDING MACHINES 4 Sheets-Sheet 3 Filed May 14, 1953 Hu o IQI

0 M ,0 n. M 0 W B 7 m mm m m m an 7 J\ /\m w, \/a m i \4. I G r .0 w n \l\ w 2 5 F Dec. 27 1955 c. A. BANKS ABRASIVE BELT CUTTER BAR GRINDING MACHINES 4 Sheets-Sheet 4 Filed May 14, 1953 INVENTOR CH/i/FLEG f7. B/INHJ United States Patent ABRASIVE BELT CUTTER BAR GRINDING MACHINES Charles A. Banks, Worcester, Mass. Application May 14, 1953, Serial No. 355,117

12 Claims. (Cl. 51-141) This invention relates to a machine for grinding adjacent edges of a mowing machine, combine or reaper and binder cutter bar or any other similarly shaped equipment that requires periodic sharpening or grinding. The type of cutter bar referred to is illustrated in Fig. of attached drawings.

The cutter bar or work is positioned in the work holder of this machine, and is fed by hand to a predetermined point which properly positions the adjacent cutting edges of each pair of sections to permit the grinding means, which in this machine is an abrasive belt, to quickly and accurately grind the proper cutting edge angle.

A primary purpose of this invention is to speed up the grinding of such cutter bars as opposed to methods and practices heretofor employed. A further primary object of this invention is to maintain, each time the cutter bar sections are reground, the original cutting edge angles on each section. Another object of this invention is to eliminate, during the grinding operation, the frictional heat usually developed by other grinding methods, thus eliminating the so-called burning or drawing the temper of the sections during the grinding operation. Another object of this invention is to provide a machine that will be available for other uses and therefore not be considered seasonal equipment.

The foregoing and other objects which will appear as the nature of the invention is better understood, may be accomplished by a construction, combination and oper ative arrangement of parts such as is disclosed by the drawings. The nature of the invention is such as to render it susceptible to various changes and modifications, and therefore, I am not to be limited to the construction disclosed by the drawings nor to the particular parts described in the specification; but am entitled to all such changes therefrom as fall within the scope of my claims.

In the drawings:

Fig. 1 is a side elevational view of my machine with portions of various parts broken away to disclose elements therebehind, and shows the grinding means in normal or inoperative position.

Fig. 2 is a front elevational view with portions of various parts broken away to disclose the operating mechanism therebehind.

Fig. 3 is a fragmentary plan view showing the abrasive belt supported by the former plates in the actual grinding position.

Fig. 4 is a sectional view taken on the line 44 of Fig. 2 and shows the abrasive belt supported by the former plates in the actual grinding position.

Fig. 5 is a fragmentary, front elevational view showing the shape of the sections of a cutter bar or work.

Fig. 6 is an enlarged sectional view taken on the line 66 of Fig. 1.

Fig. 7 is a fragmentary, rear elevational view of my machine showing the means for pivotally mounting the motor.

Fig. 8 is a fragmentary, rear elevational looking in the 2,728,173 Patented Dec. 27, 1955 direction of the line 8-8 of Fig. 1 showing the spring arrangements for providing proper tension, and the means for tracking or centralizing the abrasive belt.

Like characters of reference indicate like parts throughout the several views in the drawings. Referring to Fig. 5 the following nomenclature is applied to the various parts comprising the cutter bar which is also variously known as a sickle, knife or blade; but for the purposes of this application will be hereinafter referred to as a cutter bar K. 175 in its entirety is one section, 176 is the back bar, 177 is the rivet for fastening said sections 175 to said back bar, and 178 .is the joint between two adjacent sections. 179 and 180 are the cutting edges and 181 and 182 represent the angular surface of each cutting edge.

As illustrated in Figs. 1 and 7 my machine has a supporting means or base 10 to which is bolted a bracket 11 having two slots 13 therein by which means said bracket is secured to said base by two bolts 12. Pivotally mounted in said bracket 11 is a plate 18 in which a slot 19 runs lengthwise providing a means for adjustably securing a motor base 14 to said plate 18 by two bolts 15, which base 14 is an integral part of the usual motor M. Attached to said motor M is a drive pulley P, connected to a driven pulley 86 by a belt 86a, later described. The outer end of the motor base 14 rests on a screw 24 located in a support block 22 as shown in Figs. 1 and 7. Support block 22 is pivotally mounted on base 10 by a shouldered bolt 23. This permits support block 22 to be pivoted to bring a bolt 25 under motor base thus permitting motor M to rotate with motor pivot plate 18 around pivot point 18a to a lower rearward position thus increasing the distance from motor pulley to driven pulley for purposes that will be disclosed later.

Work holding means has a support 26 attached to one end of base 10 by two bolts 28, and a work holder 34 is attached to said support 26 by two bolts 36 which are located in two holes 36a in said work holder 34 and two holes 36b in said support 26. A short cutter bar guide 42 is attached to work holder 34 by two bolts 43. Mounted on each bolt 43 between bolt head and guide 42 is a washer 39 and a compression coiled spring 44.

This construction provides a resilient mounting for said guide 42 and is necessary to permit passage of the thick end of cutter bar when the last few teeth on said bar are brought into grinding position. Mounted on work holder 34 at either side of work holder support 26, are two fixed guides 40 attached to said work holder by two bolts 41 in each guide as shown in Fig. 2. Integral with work holder 34 is a boss or retaining member 37 which prevents the cutter bar or other workpiece K from tipping upwardly when inserted in work holder 34. An indicator or pointer 48 has a vertically elongated slot 49 through which it is adjustably attached by thumb screw 50 to work holder 34. This pointer 48 is used as a means to indicate the correct position of the joint between said sections 175 in the cutter bar being ground. When a pair of said sections 175 have been correctly located in relation to the grinding means, as will be more completely described later, said pointer is locked in position i in line with the joint between said two sections with thumbscrew 50. Then the joint of each succeeding pair of sections to be ground must be brought in line with said pointer which will locate them in the correct position for grinding.

Slidably mounted in the longitudinal slot 53 in said base 10, is a slidingmember 54 which has four outer bosses 64, two on each side, that rest on a bearing surface adjacent to each sideof the longitudinal slot 53 in base 10. At right angles to said seat or bearing surfaces said bosses project downwardly for a distance suflicient to,

provide a bearing surface against each of the two sides of said slot 53 which control the transverse motion of the slidingrnember' 54', thereby confiningthemovement' of M extend through slot 53 but have no contact with the sides.

of said slot, and which prongs 52 confine themotion of clamp 60' to a downward or upwardimotion only. Clamp 60' contains. centrally therein, a screw threaded'hole into which wing screw 62 is threaded. Tightening of said screw 62 causes clamp 60 to move vertically and thus locks sliding member 54 in any desired position within theiconfines of longitudinal slot 53.

At one end of'slidin'g member 54 are two: cars or bosses 56 located centrally between them and in an, approximate" central position vertically, is a screw threaded hole 58', operative in which hole is an adjusting screw 30 actuated by'handl'e 32. To impart'motion to said sliding member 54 the adjusting screw 30 is confined in slot 66 in'the work holder support 26, by washers 68 in contact with the opposite ends of'the slot therein, which are held in position thereat by cotter pins 70'extendingthrough said adjusting screw 30; This arrangement prevents any longitudinal movement of said adjusting screw 30 in said support 26, consequently rotation of said screw 30 imparts motion to sliding member 54 to thereby position the latter and the carrier means attached thereto as desired.

At one end of sliding member 54am two ears or bosses 56' on which is pivotally mounted a carrier connecting bracket 74 by means of the two ears or bosses 76 attached to-said bracket 74. Extending through said-bosses 56 and 76 is a pivot pin 78 held in position therein by cotter pins 80 at either end, and movably supporting carrier means, which construction permits an arcuate motion to be manually imparted to the latter means;

"Mounted in and attached to bracket 74 said carrier means has support rods 81 and 82, each being held in position in said bracket 74 by a pin 84. The upper end of rod 82 is screw threaded for a portion of its length.

Part of bracket 74 is a boss or housing 74a in which is rotatably mounted a shaft 88 and attached thereto is a pulley or drum 89. The lateral movement of said drum and shaft in said housingis confined in one direction by the hub of said drum and in the opposite direction by the shoulder of sheave or pulley 86 which is attached to said shaft 88' by a set screw 87. Pulley 86 is the driven pulleyand motion is transmitted to it through belt- 86a from pulley P attached to motor M.

As bestlindicated inFigs. land 6- positioned adjustably both longitudinally and. laterally on rods 81 and.82, approximately midway between bracket 74, andbracket 110 later described, ismounted table. support-bracket 90 attached to said rods by clamp 96. In said bracket 90 is. an elongated. slot 90a holding a screw.97atwhich-extends downwardly through a hole in clamp. 96. On said screw 97 is anut 97awhich, when tightened,alocks bracket 90' andclamp .96 securely to rods 81 and 82 in relatively any desired position. Said clamp 96 has two half round slotsspaced to match the center distance between the tworods 81' and 82. This-construction permits a lateral movement ofbracket 90 relative to rods 81 and SZ-and permits a rigid clamping of saidmembers in relatively any desired position; Integral with and at one end of bracket 90 is a boss 92. with a hole 93.extending"vertically through said boss as shown in Fig. 6.-

Extending upwardly and downwardly through said hole 93'is table rod 94 which can be adjusted vertically 'in either direction and locked in relatively .any position by". set screw 95 that is at side of said boss 92. Said ro'd'94 extends into'a mountingmeans 98and is heldtherein by set screw 99 at: thexside of-saidmounting means? Integral with :andzpartrof said mounting-means is'a table-98a.

Located. approximately central in" table 981: relative to thef'l'ateral center" of the drums 89 and 114' isia conical shaped "hole 102. Y The adjustment previously described I enemas 4 relative to bracket is provided to permit this hole to be'laterallydocated' central with saiddrums.

Located radially in respect to hole 102 are two arcuate slots 104, as best indicated in Fig. 2, which permit a radial movement of a former device, later described.

Adjustably mounted at the upper end of rods 81 and 82 is an idler drum supporting bracket 110. Holes 81a and 82a in bracket 110, through which said rods 81 and 82 pass are slightly larger than the diameter of said-rods.

This looseness or clearance is provided as a means to permit a slight adjustment in either direction of the normally parallel horizontal planes of said lower drum 89,

and an upper drum 114, later described. Said'adjustment is necessary to permit the tracking or. centralizing of abrasive belt B with said drums 114 and 89. The position of said abrasive belt relative to said drums is also affected, slightly by variables in the manufacture of the semi-floating mechanism of the forming device andvsaid adjustment also provides a means. for. compensatingfon At the lower part of bracket and.

these variables. integral with same is projection or handle 112 used to. manually actuate the carrier. unit in an arcuatepathtoits grinding position. On said bracket 110 opposite said. handle .112. is a boss or housing 110a in which is rotatably mounted a shaft 116 and attached thereto is: a pulley or. drum 114. The lateral movement of said drum and shaft in said housing is confined in one. direction by the .hub. of saiddrurn and in the opposite direction by..the face of a collar 119 attached to shaft 116 by set screw 119a.

Drum 114 is an idler, drum and motion is onlytransmitted to it when drivenpulley 86 is rotatedand abrasive: belt B is mounted thereon and under the required tension.

On bracket 110 is a small radial boss .121 located con: trally with hole 81a in thevertical plane shown in. Fig; 8. Resting against said .boss on rod 81. is awasher 120 adjacent thereto and also on .rod 81 isa compression spring, 128, held in compression on said rod. against saidwasher by a retaining collar 127 secured to said rod by setscrew 12%. The purpose of this arrangement is to provide proper tension to abrasive belt Bv and is. secured by compressing spring 128 with. collar. 127 until .the desired; tension is secured.

On rod 82 under bracket 110 and adjaceutthereto is a washer 118, a compressionspring 128a, and a retaining; collar 136 secured to. said rod. by set screw 137.. This spring is compressed'initially to alonger length. than spring 128 on rod 81. Upwardly adjacent tosbracket 110 and. on rod 82 is a washer 117,.acompression spring 128b,. a washer 130 and a retaining wing nut 132-. The wingnut; is ameans to compress springs 128a and.128b toapproX-i. mately the same compressedv length. With the abrasive belt B positioned on the drums and. the motor euergized,..

the carrier is swung toward the operating position. If,

with power applied, the belt B tends to. run. to the left on the drums, turning nut.132 counter-clockwise will cause saidbelt to track or run towardsthe right. If belt 3.

mounted in the arcuate slots 104 and stud 141:: is mounted.

in hole 102 and is retained therein by a cotter pin-.142, as shown in-Fig. 6. When it is desired to use.this -.machine for other types of service, said cotterpin.-142 is removed and the former device can then'be removed, thus.

making the machine available. for other purposes.

Resting against the shoulder of' each. ofv said-studs 141 and.141a is a washer. 14$..whichconfine: thelcornpression springs'146'on studs 141 and compression spring3'146a. on.

stud 141a. .Said studs 141 and 141a. are screw. threadedly I connected with the. screw threadedcholes .143 inatcradle. 14 4'. Extending upwardly at either end of cradle 14.4;are-

two arms 144a attheguppcr cndofrsaid-armsware two holes 152 in line with each other which provide the outer bearing support for pin 151. Pivotally mounted on pin 151 are former plates 148 and 15d and projecting downwardly from said former plates are guide bosses 148a and 156a. Approximately central longitudinally, in each of said bosses is a hole 156 somewhat larger than a right and left hand screw threaded elongate rod 158 that is retained therein. Said hole is shaped conically from the center outwardly toward opposite sides of said bosses 148a and 150a to provide clearance for the vertical motion imparted to said rod when actuated to adjust the horizontal angularity of plates 148 and 150. Screw threadedly connected to said rod 158 is a retaining nut 159 at one end and a retaining nut 159a at the other end. Inserted between said nuts and said bosses are washers 154 and resting against the inside face of said bosses are washers 154a. A connector boss 153 extends upwardly from and is in tegral with cradle 144 and contains a hole therethrough to permit passage of said rod 158. Confined on said rod 158 between said washers 154a and cradle boss 153 are compression springs 160.

To adjust my machine, referring to Figs. 1, 3 and 4, with abrasive belt B removed, the carrier means is pushed in an arcuate path around pivot pin 78 by grasping handle 112. This motion is continued until forming plates 148 and 150 are in contact with surfaces 181 and 182 of any two adjacent sections of cutter bar K shown in the grinding position on fixture bar 34. Then screw 62 is loosened and adjusting screw handle 32 is operated to move the sliding member 54 until said plates contact the two surfaces 181 and 182 or any portion thereof for their entire length. With this adjustment made screw 62 is tightened. Rod 158 is used to adjust or alter the surface angularity of plates 148 and 150 relative to each other in order to permit the surface of said plates in contact with surfaces 181 and 182 to be adjusted so that a full angular surface contact thereon will be obtained.

Following above procedure pointer 48 is positioned as previously described. When these adjustments are com pleted abrasive belt B is repositioned over both drums and the forming device. With the motor in operation, the carrier is again pushed forward until the abrasive belt B contacts the sections to be ground. At the beginning of said contact the abrasive belt starts to flex and continues to flex until it is in full contact with and assumes the shape of the forming device immediately behind it, Figs. 3 and 4. The rotation of the abrasive belt in this position quickly produces a sharp edge at 179 and 188 and if the sections have not been previously ground by other means the cutting edge angles 181 and 182 will be maintained during this and all subsequent grinding operations on my machine.

The resilient mounting of the former device on table 98a serves several purposes.

Firstly.It provides enough resiliency so that the previously described adjustment or positioning of sliding means 54 does not become a critical adjustment.

Secondly.--It permits the forming device to float and adjust itself and thereby form said belt to compensate for any reasonable misalignment, mechanical or other defects imparted to the cutter bar through use and encountered during the grinding operation.

T hirdly.It minimizes the possibility of suddenly applying too much pressure against the abrasive belt and cutter bar which might cause damage to the belt or cause it to slip or stop.

The purpose of the rotatably mounted motor and the means for adjusting said motor is to secure varying drive characteristics required when grinding cutter bars and is secured as follows.

ln Fig. l the carrier means pivoting around pivot pin 73 is shown in the rest or inoperative position. Said arion is fixed by boss 55 contacting a portion of the rl'ace of bracket 74 thereby providing a positive stop tor the rearward motion of said bracket. In this position it is desirable to have abrasive belt B motionless thereby reducing danger of injury to operator, re-

loose on pulleys P and 86 to transmit power. Adjust-,

ment of said screw 24 upwardly shortens the center distance between said pulleys and thereby loosens the belt. The reverse adjustment lengthens said center distance and therefore tightens said belt. When screw 24 is properly adjusted and with motor energised no motion is trans: mitted from motor pulley P to pulley 86with carrier in inoperative position. As the carrier unit is swung on its pivotal mounting towards the operative position, the center distance between the said pulleys lengthen and belt 86a is thereby tightened just before the grinding position is reached. Further forward motion of carrier to the grinding position, causes belt 86a to lift the motor M with the motor frame 14 off said screw 24, thereby causing a portion of the weight of the motor to provide the required belt tension on belt 86a.

As this machine can also be used as a so-called belt sander and therefore used for other purposes it is necessary to provide power for its operation when said carrier is in its rearmost position. the rear of motor is lifted sufliciently to permit bracket 22 to be swung around thereby positioning screw 25 therein under the motor frame 14 for its rearward support. Said screw 25 is adjustable in either direction in the vertical plane and permits the motor to pivot downwardly radially about pivot 18 thereby tightening belt 86a causing same to transmit power to pulley 86. Positioned in this manner the abrasive belt and the motor operate in unison. Starting and stopping the motor also starts and stops said abrasive belt.

What I claim is:

1. A grinding machine comprising supporting means, means mounted on and extending upwardly from said supporting means embodying a work holder at the upper part thereof, carrier means extending upwardly from and movably supported by said supporting means and normally spaced from and movable relative to said work holder, said carrier means embodying a mounting and a mechanism to provide translational movement of an abrasive belt, a former device attached to said mounting embodying two face members hingedly connected to gether and extending diagonally in opposite directions from said connection and being adjacent to and to one side of the path along which said belt is adapted to pass, said face members having adjustable means for varying their relative angular disposition and a floating means to permit variation in their longitudinal angularity, permitting said face members to conform to the shape of said workpiece when pressed against a portion of said belt and against said workpiece, said face members being laterally opposite a portion of said work holder.

2. A grinding machine comprising supporting means, carrier means movably supported by and extending upwardly from said supporting means embodying two.

pulleys to receive and provide translatory movement of an abrasive belt and embodying a supporting bracket supporting one of said pulleys, two supporting rods slidably connected to said bracket and supported by said carrier means, said bracket having provision in cooperation with adjusting nut engaging threaded portion of one of said rods to permit tilting movement of said bracket, and adjusting members movably attached to said rods and bearing against portions of said bracket cooperating with said provision whereby upon adjustment of said members the position of said bracket on said rods may be changed.

3. A grinding machine comprising supporting means,

To accomplish this belt, and embodying-a supporting bracket having two holestherein, and embodying two supporting rod-s passing through said holes, two-coilsprings on one of said ro'dscabove-rand below andb'earing against different portions ofsaidbracket, two retaining members of said rod, bearing againstw said two springs respectively one of which. retaining members is adjustable on said rod, said holes being of 'suflicient diameter. relative to that of said rodsso that the latter'have clearance therein whereby theposition of said bracket on said rods may be varied by moving saidadjustable retaining member on said rods to: thereby adjust-thetension of said two springs.

4; A grinding machine'cornprising supporting means, carrier means'extending upwardly from and movably supported bysaid supporting means embodyinga mechanism to receive andprovide translational movement of an abrasive belt and embodying a supportingbracket having two holes= therein and embodying two supporting rods passing through said holes, a coil spring on one of said rods below and-bearing-against saidbracket, a retaining member on said rodretaining said spring in predetermined position, two coil springs on the second of said rods above-and below and bearing against different portions of said bracket, two retaining members on said second namedrod bearing against said two" springs respec tively one ofwhich' retaining members is adjustably mounted,- said holes being of sufficient diameter relative to that of said rods so'that the latter-have clearance therein whereby the position of said bracket on said rods may be varied by-moving said adjustable retaining member on said second named rod to thereby adjust the tension of s'aid two springs mounted-thereon.

5. A- grinding machine 'comprisingsupporting means, carrier means movably supported by said supporting means embodying a mountingand-a mechanism to receive and provide translatory motion of an abrasive belt, a former device embodying a cradle having an opening therethrough, means connecting saidcradle to said mounting, two face members movably connected together and extending away from the connecting point at opposite sides thereof; each said face member embodying a guide member at anouter portion thereof each having a hole therethrough' and an elongated pin member extending through said latter holes and cradle opening, and compression means on said elongated pin'member adapted to be actuated by movement of said face member and its said guide member when pressure is applied to said face member.

6. A grinding machine comprising supporting means, carrier means movably supported'by said supporting means embodying a mounting and a mechanism to receive and provide translatory movement of anabrasive belt, a former device embodying a cradle having a hole therethrough, means-connecting said cradle tosaid mounting, two face members movably connectedtogether and extending away from the connecting point at opposite sidesthereof, each'said face'memberembodying a guide member at an outer portion thereof each having a-hole therethrough, and an elongated'pin member extending through said" latter holes and cradle opening, and two 'coil springs on saidelongated pin member between said guide membersand different portions of said cradle, adapted to be actuated bymovement of said face members and said guide memberswhen pressure'is applied to said face members.

7. A grinding-machine comprising supporting means, carrier means movably supported by said supporting means embodying a mounting and'a mechanism to provide translatory motion of an abrasive belt, a former device embodying a cradle, means connecting said-cradle to said mounting, twofacernernbers connected together and extending away from the connecting point at oppositesides thereof, a-cradleembodying-a portion-rearwardiy of said'face membershaving a laterallyextendingsltitformed thereon; each said face member embodying a guide member at an outer portion thereof each having a laterally extending hole therethrough', an elongated pin member screw threaded at each end extending through all of said laterally extending holes, means associated with said pin member for adjusting'the angular-position of said face members, and compression means on said elongated pin ing two arms and a connector boss having an opening therethrough, pin members connecting said mounting and cradle, two face members pivotally connected tosaid two arms and extending away from the connecting point at loosely through said guide boss and connector boss holes,

two coil springs on said elongated pinmember and screw threaded adjusting members on said elongated pinmemher at opposite end portions thereof outside of said guide bosses, said coil springs being between and bearing against said guide bosses and connector boss, each said face member, when pressure is applied thereto, being adapted to individually move as a said guide boss moves on said elongated pin member.

9. A grinding machine comprising supporting means, Workholding means supported by said supporting means, carrier means moveabiy supported by said supporting means and spaced from and moveable relative to said work holding means and embodying'a mounting and amechanism providing translatory motion of an abrasive belt, a former device attached to said mounting embodying a cradle having a connector boss extending parallelv with said arms and having an opening therethrough and two arms extending parallel; withrand beyond said connector boss, means connecting said mounting and cradle, two face members pivotally connected to said two arms and extending away from the connectingpoint at opposite sides thereof, each saidface member embodying a guide boss having an opening therethrough, an elongated pin member extending loosely through saidguide boss and connector boss openings, two coil springson said elongated pin member, and screw threaded retaining members on said elongated pin member at opposite end portions thereof outside of said guide bosses, said coil springs being between and bearings against said guide bosses and connector boss, each said face member, when-pressure is applied thereto, being adapted to individually move as'a said guide boss moves on said elongated pin-member 10. A grinding machine comprisingsupporting means, means mounted on said supporting means for holding a workpiece, carrier means movably supported by said supporting means and embodying a mounting having a table and a mechanism providing translatory movement ofan abrasive belt, said table having a substantially circular hole therethrough and having'two slots therethrough radially located with respect to and at opposite side ofv said hole, a former device attached to said table embodying face means adjacent to and toone side of the path of said abrasive belt, said face means being adapted to.

shape aportion of said belt in conformity thereto when pressed into contact therewith, said former device embodying a cradle having three holes therein opposite the said hole and two slots in said table when in assembled position, three pins movably extending into said-hole and said two slots in said table and-screwthreadedly COD-r nected to said cradle to thereby-attach-said cradle 'tosaid table.

11'. A grinding machine comprising supporting3means,

mechanism providing translatory movement of an abrasive belt, said table having a substantially circular hole therethrough and having two slots therethrough radially located with respect to and at opposite sides of said hole, a former device attached to said table embodying face means adjacent to and to one side of the path of said abrasive belt which face means is adapted to bear against an under portion of said belt and to shape the working surface of said belt in conformity therewith when pressed into contact therewith, said former device embodying a cradle having three holes therein opposite the said hole and two slots in said table when in assembled position, three pins movably extending into said holes and slots in said table and cradle to thereby attach said table and cradle, and coil springs on said pins and bearing against said table and cradle.

12. A grinding machine comprising supporting means, carrier means movably supported by said supporting means and embodying a mounting having a table and a mechanism providing translatory motion of an abrasive belt, said table having a substantially circular hole there through at an upper portion thereof in position of use and having two slots therethrough radially located with respect to, and at opposite sides of, said hole, said slots being located in a lower portion of said table, a former device attached to said table embodying face means adjacent to and to one side of the path of said abrasive belt which face means is adapted to shape a portion of said belt in conformity thereto when pressed into contact therewith, said former device embodying a cradle having three holes therein opposite the said hole and two slots in said table when in assembled position, three pins movably extending into said holes and slots in said table and cradle to resiliently attach said table and cradle, and coil springs on said pins and bearing against said table and cradle.

References Cited in the file of this patent UNITED STATES PATENTS 552,066 Leach Dec. 24, 1895 973,059 Marten et a1 Oct. 18, 1910 994,358 Wysong June 6, 1911 1,124,311 Mattison Jan. 12, 1915 1,179,999 Blevney Apr. 18, 1916 1,974,806 Curtis et al Sept. 25, 1934 2,120,880 Yung June 14, 1938 2,197,077 Littlefield Apr. 16, 1940 2,232,149 Tantz -u Feb. 18, 1941 2,251,110 Bright July 29, 1941 2,573,220 Riedesel et al Oct. 30, 1951 

